1. Field of the Invention
The present invention relates to the technology of manufacturing an electrical connector, and particularly to the technology of manufacturing the electrical connector having retention contact tails for retaining the connector onto a printed circuit board (PCB) before the connector is soldered onto the PCB and non-retention contacts tails for reducing the force of inserting the contact tails to the PCB.
2. Description of the Related Art
Typical board retention designs require an interference feature into a hole on a printed circuit board (PCB). This can be accomplished with separate retention pins, for example, and board locks. Separate retention pins add to the overall product cost and take up extra space thereby adding to the size of the connectors. So, there is a trend of using contact tails to accomplish the retention feature. In order to keep manufacturing and assembly costs minimal, typically all retention pins exhibit the same geometry. This leads to having all the contact tails provide retention but not all. This approach has the negative impact of increasing the insertion force. Ideally, it would be beneficial to have some contact tails accomplish the retention feature and the other contact tails do not accomplish the retention feature, thereby permitting flexibility in the insertion and retention characteristics of the connectors.
U.S. Pat. No. 5,411,404, issued to THE WHITAKER CORPORATION, discloses an electrical connector having contact tails with retention feature and contact tails without retention feature. However, the retention feature contact tails and the non-retention feature contact tails have different geometries created by hard tooling, dies, and the geometries cannot be readily changed from one to the other. This adds to the manufacturing cost of the connector. Hence, an improved electrical connector whose retention feature contact tails and the non-retention feature contact tails can be created in the same tools will overcome the disadvantage of the prior art.
A first objective of the present invention is to provide an electrical connector having conductive contacts, some of which have a retention feature while others do not have a retention feature and both can be manufactured in the same tools, thereby reducing the manufacturing cost.
A second objective of the present invention is to provide an electronic device including a printed circuit board (PCB) and the aforementioned electrical connector retained onto the PCB.
A third objective of the present invention is to provide a method of manufacturing the conductive contacts of the aforementioned electrical connector.
To fulfill the above objectives, an electrical connector including an insulative housing and a plurality of contacts attached to the housing was invented. The contacts each have a contact tail downwardly extending beyond a mounting surface of the insulative housing for inserting into a throughhole of the PCB. The contact tails are overlapped in pairs and each pair of contact tails is inserted into the same throughhole of the PCB. Some pairs of contact tails, called retention contact tails, have protrusions deviating from each other for bearing against the peripheral walls of the throughholes of the PCB thereby producing retention force. The other pairs of contact tails, called non-retention contact tails, do not have protrusions and do not interfere with the peripheral walls of the other throughholes of the PCB thereby producing no retention force. The retention contact tails can be modified to be non-retention contact tails by deforming the protrusions. In the first embodiment, the protrusions are sheared off. In the second embodiment, a portion of the contact tip having the protrusions is removed to provide a lead in chamfer for aiding in alignment of the contact tails to the holes of the PCB. In the third embodiment, the protrusions are swaged into notches of the other corresponding contact tails. The tail portions may be embedded in the plated holes or extend through the PC board, which is determined by thickness of the PC board and the length of the tail portions.